Answer this question truthfully
### Question: What causes Hemophilia?
### Response: Hemophilia A is caused by an inherited X-linked recessive trait, with the defective gene located on the X chromosome. Females have two copies of the X chromosome, so if the factor VIII/ IX gene on one chromosome doesn't work, the gene on the other chromosome can do the job of making enough factor VIII/ IX. Males, however, have only one X chromosome, so if the factor VIII/ IX gene on that chromosome is defective, they will have hemophilia. Thus, most people with hemophilia are male.
If a woman has a defective factor VIII/ IX gene, she is considered a carrier. This means the defective gene can be passed down to her children. In a woman who carries the defective gene, any of her male children will have a 50% chance of having hemophilia A, while any of her female children will have a 50% chance of being a carrier. All female children of men with hemophilia carry the defective gene. Genetic testing is available for concerned parents.
Rarely, adults can develop a bleeding disorder similar to hemophilia. This may happen:
after giving birth (postpartum), in people with certain autoimmune diseases such as rheumatoid arthritis, in people with certain types of cancer (most commonly lymphomas and Leukemia (patient information)leukemias), also for unknown reasons (called "idiopathic").
Although these situations are rare, they can be associated with serious, even life-threatening bleeding.